Optimal Migration Routes of Dusky Canada Geese: Can They Indicate Estuaries in British Columbia for Conservation? by Christina J. Kereki B.Sc. Biology, University of Victoria 1999 RESEARCH PROJECT SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF RESOURCE MANAGEMENT In the School of Resource and Environmental Management of the Faculty of Applied Sciences Project No. 420 © Christina J. Kereki 2007 SIMON FRASER UNIVERSITY Spring 2007 All rights reserved. This work may not be reproduced in whole or in part, by photocopy or other means, without permission of the author. APPROVAL Name: Christina Jane Kereki Degree: Master of Resource Management Title of Research Project: Optimal Migration Routes of Dusky Canada Geese: Can They Indicate Estuaries in British Columbia for Conservation? Project No.: 420 Examining Committee: Chair: Shelley Marshall Master’s Candidate School of Resource and Environmental Management ______________________________________ Dr. Kristina D. Rothley Senior Supervisor Assistant Professor School of Resource and Environmental Management Simon Fraser University ______________________________________ Dr. Robert W. Butler Supervisor Adjunct Professor Biological Sciences Simon Fraser University Date Defended/Approved: ______________________________________ ii ABSTRACT In response to increasing threats, habitat loss, and degradation of British Columbian (BC) estuaries, the Pacific Estuary Conservation Program (PECP) protects estuaries through land acquisition and stewardship programs. To assist the PECP in prioritizing BC estuaries, I develop a conservation tool that exclusively considers estuarine significance within a reserve network for migrating waterfowl. Using a dynamic state variable (DSV) optimization model, I predict estuary stopovers used by Dusky Canada Geese (Branta canadensis occidentalis) during spring migration. The DSV model predicts that only geese beginning migration in poor condition with respect to fat deposition use estuaries to maximize expected fitness. Numerous versions of the DSV model identify the Fraser River Estuary as an important stopover for geese of initially lower energy reserves. Introducing the assumption of density-dependence increases the total number of estuaries used as stopovers. Postulated scenarios of estuarine habitat losses decrease expected fitness more than scenarios of population increases. Keywords: estuaries; waterfowl migration; Dusky Canada Goose; Branta canadensis occidentalis; dynamic state variable model; conservation planning iii DEDICATION To my mother and father, Waltraud and Gyula Kereki, for their steady support all these years. And to my new family, Bernardo Alonso for his thoughtful insight on things that matter. iv ACKNOWLEDGEMENTS I thank my supervisory committee, Dr. Kristina Rothley and Dr. Rob Butler for their advice, support, and encouragement. This project would not have been possible without collaboration with Kristina; her modelling expertise was invaluable. I thank Rob for his advice concerning matters of bird ecology, which helped me to think critically about the inputs for a migration model that could generate meaningful predictions. I thank Ducks Unlimited Canada for providing the dataset of British Columbian estuaries and project funding. I extend my thanks to Dan Buffet, who relayed the Pacific Estuary Conservation Program’s need for this research, and sparked the germination of the original project idea. Dan also provided me with useful data, reports, and advice along the way. I thank Bird Studies Canada and the Canadian Wildlife Service, Environment Canada for supplying the BC Coastal Waterbird Survey data. I also thank all volunteer participants who gathered these data, and Peter Davidson who compiled the information. I thank the Meteorological Service of Canada, Environment Canada for supplying BC coast weather data. Pat Wong and Maria Petrou were very helpful in providing access to these data. I appreciate the efforts of Jerry Hupp (USGS Alaska Science Center) and Tom Rothe (Alaska Department of Fish and Game) in contributing information and advice for the derivation of goose parameters. Thank you. Finally, I say thank you to the Applied Wildlife Ecology Lab for their comradery during the past two and a half years. I have appreciated the lab’s positive environment of sharing research and ideas. I have learned a lot from you all. v TABLE OF CONTENTS Approval ............................................................................................................................ ii Abstract .............................................................................................................................iii Dedication ........................................................................................................................ iv Acknowledgements ........................................................................................................... v Table of Contents............................................................................................................. vi List of Figures..................................................................................................................viii List of Tables.................................................................................................................... xi 1 Introduction.............................................................................................................. 1 Background ....................................................................................................................... 4 The Importance of Conservation Planning................................................................. 4 Methods in Selecting Sites for Conservation ............................................................. 5 The Importance of Including Animal Behaviour in Site Selection Methods................ 7 Investigating the Use of Bird Migration in Conserving Estuaries ............................... 8 Applying Dynamic State Variable Models ................................................................ 12 2 Methods .................................................................................................................. 15 Study System .................................................................................................................. 15 Spatial Data Inputs.......................................................................................................... 17 Model Development ........................................................................................................ 18 Conceptual Migration Model .................................................................................... 18 Quantifying the Dynamic State Variable Migration Model........................................ 21 Model Versions ........................................................................................................ 26 Model Evaluation............................................................................................................. 29 Sensitivity Analyses ................................................................................................. 29 Model Validation ...................................................................................................... 31 Model Application............................................................................................................ 32 Forward Iteration: Simulation of Bird Migration Across the Landscape ................... 32 Asking Questions About Waterfowl Management.................................................... 40 3 Results.................................................................................................................... 42 Predictions of Optimal Migration Routes......................................................................... 42 Migration Strategies................................................................................................. 42 Estuary Site Use ...................................................................................................... 46 Sensitivity Analyses ........................................................................................................ 53 Effects on Relative Fitness ...................................................................................... 53 Effects on Trip Length and Number of Intermediate Stopovers............................... 56 Effects on Estuary Sites Identified as Stopovers ..................................................... 58 Model Validation.............................................................................................................. 60 vi Density-Dependent Effects in the Forward Iterations...................................................... 63 Effects of Waterfowl Management and Estuarine Losses on Migration and Survival ........................................................................................................................... 67 Applying Population Scenarios to Goose Migration................................................. 67 Applying Scenarios of Estuarine Losses to Goose Migration .................................. 71 Altering the Density-Dependent Assumption ........................................................... 78 4 Discussion.............................................................................................................. 80 What Does the DSV Migration Model Predict for BC Estuaries? ...................................